Optical diagnostic instrument



' May 3 1927.

' 6 1,626,601 CLEMENT OP'iICAL nmcuosuc msmmsm Filed July 15. 1925 I N VEN TOR.

mm s (m /0w A TTORNEYS patients eye. J

Patented May 31,1927.

HANS CLEMENT, on NEW OPTICAL {DIAGNOSTIC INSTRUMENT.

Application filed J'uly 15, 1925. Serial No. 43,727.

a mirrors inclined 45 to the axis oflthe light and provided with a sightopening through which the observer looks in examiningthe illuminatedarea, such as the pupil of the This sight opening often resultsin moreor. less interference wlththe reflection of the light and with theobservers vision. An

reflector substantially avoids the halo effects characteristic of thecentral round observation hole, but the lessened illumination of theareaobserved'due'to the slot in the re- V I v scope is mountedonthebattery-containing Y i-in electric flector is quite pronounced, andso the slot substantially detracts from the efficiency of theinstruments By my inventionl ani able to employ merely a small centralsightopening in the reflectoruand thus deprive the reflector of aminimum area ofreflecting surface, and at the same time 1am able toavoid the objectionable halo effects due to refractionand reflection ofthe light about the edge of the sight opening. Moreover, my inventionenables me to eliminate or reduce to a negligible minimum the passage ofdirect rays through the sight openingback of the reflector.

In accordance with my invention I make the reflector in two partsdividing on a more orless central horizontal line, and the upper.

edge of the lower member is in the form of an acute angle. An acceptableform for this reflector is a right angle triangle prism with thehypotenuse as the reflecting surface. In the upper angular edge is aslot forming the sight opening, and the walls of this slot may be coatedwith an opaque material, thus excluding the light from the sightopening. Due to the angular shape of the side walls of the slot noshadow is thrown on the upper reflecting surface above the sightopening, as would be the case if the opaque coating for the sightopening were in the form of a cylinder. In order to avoid refraction ofthe light on the lower surface of the uppermember where it forms ineilect' the top of the sight opening, and thus interfere with the clearvision-of the spot illuminated by the reflected light, this lowersurface may be polished. In fact the upper member may; also be a rightangle triangle prism disposed so that its hypotenuse-isthe reflectingsurface andcooperates withthat of the-lower member. I -1 shallnowdescribe the illustrated embodiment of my invention andishall thereafter point out my invention/in claims. Fig. 1 is" a partial elevationand partial section or an ophthalmoscope containing an einbodimentof myinvention, if Fig. 2 is an enlarged sectional elevation ofthe upper partof the objection tubeand contained parts. Fig. 3 is a rear elevation ofthe reflector as mounted in the tube which is shown 1n section. j Theobjective tubal-of the ophthalmohandle 2 in the usua-lw'ay, and has atits upper end an objective lens] lamp 4 within the. tube serves as thesource of light. Themeans whereby the lamp and obj ective lensarerelatively adjustable to. 85 since such means are common. and form-no vvary the distance between them isnot shown,

part "of the present-invention. ri reflector 5. ismounted above theobjective-lens 3 in linew hi a s ght p n n 6. i i ei g. This reflector5. in'the form illustrated consists of two total reflecting prisms 7 and8, the hypotenuse of the two prisms being silvered and forming v asingle reflecting plane, which is at an angle of substantially 45 to theaxis, of the lensS, so as-to reflect the lightat substantially an angleof 90 to the incident rays.

In substantially the center of the top edge of the prism 7 is a slot 9forming an observation opening. The Walls of this slot are coatedwitha's'uitable opaque and non-reflective material, such as dead blacklacquer or thin sheetv metal shaped to conform to i side and bottomwalls; It'is obvious that the hypotenuse of the'prism Sneed not ofnecessity be the same plane as that of the prism 7, the only requisitebeing that the two prisms be so arranged that direct, light will notpass between them behind the reflecting surface. It is also obvious thatthe reflectr ing members may be of other shape than prismatic and thatother modifications may be made in the construction shown in thedrawings and particularly described-within the principle and} scope ofmyinvention;

'I'claima' 1 1 In an optical diagnostic instrument, in combination witha light source and alens, agreflector for thelight comprising tworefleeting prisms with the hypotenii oblique to 1 the';' axis of thelens and cooperative to form a plane reflectingsurface, theprism nearerthe lens having a slot for a; sight opening in the solid angle; farthesti from the lnsi i" r 2. Invanoptica-ldiagnostic instrument, in

combination with a light; source and a lens,

airefl'e'ctorfor the light comprising two re fleeting prisms i with thehy'po-tenii oblique to the; axis o'f the lens and cooperative tomemberhaving, a hole thereth-rough andthe v forma plane reflectingsurface, the prism nearer the lens having a slot for a sight opening inthe solid angle 1 thereof 'farthest fromthe-lens, andan-opaq-ue coatingfor the slot. a

' 3; In anoptical diagnostic instrument, in combination witha lightsource and alens,

a; reflector for the light=-comprising two refleeting prisms vwith thehypotenii- -forming a single reflectingplfane oblique to the axis ofthe-lens, the prism [nearer the lens-having a slot: for a sight"opening; in the solid angle thereof farthest-from the lens a Inanoptical; diagnostic instrument, in combination with r a light source,a reflector for the light; comprising a; silvered glass its lowersurface walls of the hole; covered; with an; opaque material.

5.v In. an optical diagnostic instrument, in o' combination withl'alight source, areflector for theligl t divided horizontally into twoparts, the lower memberhaving a slot in its upper; edgeforming a sightopening and the upper member having its lower: surface pohshedi a i i I6. In an optical diagnostic instrument, inv combinat on Wltll 2t l1gl1tsource, a: reflector.

for the light divided horizontally into two parts, the lowormemberhaving a slot in it's upper edge forming a-sight opening and; the uppermember having its lower surface polishechand air-opaque coating for theslot.

7. In an optical diagnostic instrument, in I combination, with alightsource, areflector for the light divided horizontally into: two a thelight, the lower partof'tlie reflector havi.

ing for its upper edge aniacutesolid Sangle with a slot therein :forminga sight, opening and the upper part of: the reflector: having polished,and an; opaque coating in the slot.

Inan optica'Idiagnosticinstrument; the

combination of a light source-, a condensing lens anda singlereflecting-surface. comprlsing a stepped total {reflecting prlsm, amedian sight operiingtherethrough and an opaque non reflecting liningtherein;

Inw-itness whereof I hereunto subscribe,

my signature Hans I

